21526005 has 16 divisors (see below), whose sum is σ = 34570944. Its totient is φ = 11437440.

The previous prime is 21525991. The next prime is 21526007. The reversal of 21526005 is 50062512.

It is not a de Polignac number, because 21526005 - 2⁴ = 21525989 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21526007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1662 + ... + 6768.

It is an arithmetic number, because the mean of its divisors is an integer number (2160684).

Almost surely, 2^21526005 is an apocalyptic number.

It is an amenable number.

21526005 is a deficient number, since it is larger than the sum of its proper divisors (13044939).

21526005 is a wasteful number, since it uses less digits than its factorization.

21526005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5396.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21526005 is about 4639.6125915856. The cubic root of 21526005 is about 278.1769528837.

Adding to 21526005 its reverse (50062512), we get a palindrome (71588517).

The spelling of 21526005 in words is "twenty-one million, five hundred twenty-six thousand, five".